Fears go in and out of fashion. Oh sure, some are as classic and ingrained as a little black dress – snakes, spiders, sharks, tornadoes – but others rise and fall with humanity’s levels of education and understanding. We’ve been frightened of comets, demons, Jews, dragons, witches, Catholics, elves, and a flat earth. As the modern era has progressed, boogeymen we’ve dropped in the name of enlightenment have been readily replaced with other phobias and panics that will probably / surely look as ridiculous to our descendants as pre-modern terrors appear to us.

One such intriguing thumps-in-the-night are the little green men that have been snatching unsuspecting people from their ordinary lives, and taking them into their spaceships. There, they perform various experiments – often sexual in nature – before releasing their human prey back into the wild with a bout of missing time, a nosebleed, and a sore bottom.

Alien abduction stories have been a persistent, inexplicable phenomenon since the 1960s. Now, it should be said that a handful of such tales appear earlier (including one from the 19th century), and Carl Sagan suggested that early “demon abduction” stories spring from the same “shared [human] delusion” (though if you’re a believer, you might argue demons are simply what a medieval mind called aliens, and they’ve been here all along). But the alien abduction became a popular topic of study, ridicule, and fiction in the ‘60s, and only grew in speculation and fervor through the ‘70s, ‘80s, and ‘90s. Thanks to television movies (“The UFO Incident”), blockbuster movies (“Fire in the Sky”), and unsettling bestsellers (Whitley Strieber’s “Communion”), plenty of sane and rational people had a theory on aliens, abductions, and what they wanted from us.

Looking back, the cultural watershed of pop culture aliens may have been the ‘90s. “The X-Files” was on the air, Spencer’s Gifts was always stocked full of alien kitsch, UFOlogists found fertile sharing ground on the baby Internet, “Independence Day” thrilled us, and the 50th Anniversary of Roswell earned a TIME Magazine cover. For some reason, almond-eyed aliens were the stuff of both nightmares and jokes, and we were all sure they had been here … or would be arriving soon. We agreed with Agent Fox Mulder – the truth was out there, and our governments had been covering it up.

But all that changed, and if you had to pinpoint a very precise moment, it would probably be September 11th, 2001. Oh, it had undoubtedly been dying off before then – “The X-Files” was gasping, aliens were becoming more the stuff of comedies like “Evolution” and “Galaxy Quest”), but collective fears of little green men seems to have crumpled in an instant. You can see this in the ratings for “The X-Files” itself, which planned on recasting its leads, but which plunged so rapidly in ratings (Season 9 premiered a month to the day after 9/11 ) that the show wrapped for good in May 2001. Creator Chris Carter, apparently unaware of our new reality, was incredulous. “We lost our audience on the first episode. It’s like the audience had gone away and I didn’t know how to find them.”

Isn’t it obvious? How could we be scared of anything “The X-Files” could cook up, now? Attack had come, and from the sky, but it was decidedly earth-based and ideological. We knew our attackers. We were indeed vulnerable, but not in the “superior technology” ways we had fancied and feared. The regard in which we were weak was devastatingly obvious. All it took was a regular airplane, not a Death Star or laser beam.

As the 2000s have marched on, alien abduction stories appear downright old-fashioned. While UFOlogy is still a thing, pop culture seems disinterested in missing time and metal implants. A video purporting to show an alien could make your nightly news; now it barely causes a stir on YouTube. Pop culture has never quite returned to those (in retrospect) happy-go-lucky days when we had time and space to indulge in fantasies of UFOs and alien abductions. It’s obvious why we were obsessed with that stuff – the economy was good, there were no wars, the Internet was new, and we literally had nothing better to do than imagine what our government was hiding from us. That we could go no further than aliens-in-Roswell seems incredibly naïve now. Now drones, misplaced memos, and bad WMD intelligence are the stuff of nightly news, and it makes the machinations of Cigarette Smoking Man seem pretty lame.

Now, it’s not as though there haven’t been alien abduction and invasion movies. But the most successful ones had a decidedly post-9/11 bent. Some of the biggest scares in “Signs” come from the television set, echoing the way we’d watched the worst news of our lifetime. Significantly, the first reaction people have to the destruction of Steven Spielberg’s “War of the Worlds” isn’t that it’s aliens, but that it’s terrorism. “District 9” imagines our otherworldly visitors as refugees, and easy to dominate and torture. It’s like the “Zero Dark Thirty” version of “The X-Files.”

The few old-school alien abduction stories have fallen flat on their face. “The Fourth Kind” met with a tepid response, no matter how soberly Milla Jovovich tried to convince us she was presenting “actual archived footage,” and warned it would be “extremely disturbing.” It was 2009. Grainy footage of people sweating over “the men in the stars” wasn’t upsetting; we’d seen much worse. “The X-Files” became self-aware when it tried to come back on the big screen, offering up monsters instead of aliens. If that wasn’t enough of a death knell, “Indiana Jones and the Kingdom of the Crystal Skull” tossed Mulder’s brand of obsession back into the ‘50s, underscoring extraterrestrial intrusion as an actual relic. “Cowboys and Aliens” offered a similar abduction retrograde, rendering it so unthreatening that we were able to defeat our captors with six-shooters.

This past weekend, “Dark Skies” gamely tried to run with an old-fashioned alien abduction story, and fell flat, despite a marketing campaign that tried to hide the origin of Keri Russell’s paranormal woes. Was it ghosts? Was it a curse? Was it aliens? Was it an alien ghost curse? No matter. Audiences appear to have figured it out – “Dark Skies” isn’t likely to be about demonic possession – and steered clear, preferring to laugh the all-too common woe of identity theft.

The failure and disinterest in movies like “Dark Skies” makes us wonder whether the alien abduction movie can ever come back. Will we ever lie in bed, fretting for our internal organs and sanity again? It seems impossible to believe that our socio-political climate completely outstripped a fear of black-eyed beings from beyond the stars. After all, people were devouring such lurid tales during the days of Watergate, Vietnam and the Cold War – arguably an era as unsettling as now – and yet we seem to have pushed abductees aside, scoffing, relegating them to the same kind of embarrassing mass hallucination that prompted witch trials. Perhaps it has less to do with politics than technological advances. If everyone is packing a camera in their pocket, then where are our alien videos? We suddenly have a real absence of mysterious lights in the sky, and strange figures in the desert, which may be why few filmmakers are doing found-footage alien films. There’s no thriving culture of video based debate and belief as there are with ghosts.

When it comes to jump scares, we’re preferring our thrills to be domestic and mystical (ghosts, exorcisms, curses) or contagious and biological (zombies). Have we really lost our fear of being captured, poked, and tagged, like a sullen grizzly bear, by a superior species? Are we, as Mulder once fretted, “now deaf to the realms of extreme possibilities”? Or is it all one renaissance of repressed memory, eerie MARS Rover shadow, and viral video away? The truth is out there.